diff --git a/bitcask.go b/bitcask.go
index 625fb23..88827cf 100644
--- a/bitcask.go
+++ b/bitcask.go
@@ -8,7 +8,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"time"
 
 	"github.com/gofrs/flock"
 	"github.com/prologic/trie"
@@ -57,14 +56,14 @@ func (b *Bitcask) Get(key string) ([]byte, error) {
 		df = b.datafiles[item.FileID]
 	}
 
-	e, err := df.ReadAt(item.Index)
+	e, err := df.ReadAt(item.Offset)
 	if err != nil {
 		return nil, err
 	}
 
-	crc := crc32.ChecksumIEEE(e.Value)
-	if crc != e.CRC {
-		return nil, fmt.Errorf("error: crc checksum falied %s %d != %d", key, e.CRC, crc)
+	checksum := crc32.ChecksumIEEE(e.Value)
+	if checksum != e.Checksum {
+		return nil, fmt.Errorf("error: checksum falied %s %d != %d", key, e.Checksum, checksum)
 	}
 
 	return e.Value, nil
@@ -78,12 +77,12 @@ func (b *Bitcask) Put(key string, value []byte) error {
 		return fmt.Errorf("error: value too large %d > %d", len(value), b.opts.MaxValueSize)
 	}
 
-	index, err := b.put(key, value)
+	offset, err := b.put(key, value)
 	if err != nil {
 		return err
 	}
 
-	item := b.keydir.Add(key, b.curr.id, index, time.Now().Unix())
+	item := b.keydir.Add(key, b.curr.id, offset)
 	b.trie.Add(key, item)
 
 	return nil
@@ -211,7 +210,7 @@ func Merge(path string, force bool) error {
 				continue
 			}
 
-			keydir.Add(e.Key, ids[i], e.Index, e.Timestamp)
+			keydir.Add(e.Key, ids[i], e.Offset)
 		}
 
 		tempdf, err := NewDatafile(temp, id, false)
@@ -222,7 +221,7 @@ func Merge(path string, force bool) error {
 
 		for key := range keydir.Keys() {
 			item, _ := keydir.Get(key)
-			e, err := df.ReadAt(item.Index)
+			e, err := df.ReadAt(item.Offset)
 			if err != nil {
 				return err
 			}
@@ -304,7 +303,7 @@ func Open(path string, options ...func(*Bitcask) error) (*Bitcask, error) {
 
 			for key := range hint.Keys() {
 				item, _ := hint.Get(key)
-				_ = keydir.Add(key, item.FileID, item.Index, item.Timestamp)
+				_ = keydir.Add(key, item.FileID, item.Offset)
 				trie.Add(key, item)
 			}
 		} else {
@@ -323,7 +322,7 @@ func Open(path string, options ...func(*Bitcask) error) (*Bitcask, error) {
 					continue
 				}
 
-				item := keydir.Add(e.Key, ids[i], e.Index, e.Timestamp)
+				item := keydir.Add(e.Key, ids[i], e.Offset)
 				trie.Add(e.Key, item)
 			}
 		}
diff --git a/datafile.go b/datafile.go
index 8139708..a0168f5 100644
--- a/datafile.go
+++ b/datafile.go
@@ -5,7 +5,6 @@ import (
 	"os"
 	"path/filepath"
 	"sync"
-	"time"
 
 	"github.com/pkg/errors"
 
@@ -128,8 +127,7 @@ func (df *Datafile) Write(e pb.Entry) (int64, error) {
 	df.Lock()
 	defer df.Unlock()
 
-	e.Index = df.offset
-	e.Timestamp = time.Now().Unix()
+	e.Offset = df.offset
 
 	n, err := df.enc.Encode(&e)
 	if err != nil {
@@ -137,5 +135,5 @@ func (df *Datafile) Write(e pb.Entry) (int64, error) {
 	}
 	df.offset += n
 
-	return e.Index, nil
+	return e.Offset, nil
 }
diff --git a/entry.go b/entry.go
index 3d14597..ad81d1d 100644
--- a/entry.go
+++ b/entry.go
@@ -7,11 +7,11 @@ import (
 )
 
 func NewEntry(key string, value []byte) pb.Entry {
-	crc := crc32.ChecksumIEEE(value)
+	checksum := crc32.ChecksumIEEE(value)
 
 	return pb.Entry{
-		CRC:   crc,
-		Key:   key,
-		Value: value,
+		Checksum: checksum,
+		Key:      key,
+		Value:    value,
 	}
 }
diff --git a/keydir.go b/keydir.go
index bc38c03..308f951 100644
--- a/keydir.go
+++ b/keydir.go
@@ -9,9 +9,8 @@ import (
 )
 
 type Item struct {
-	FileID    int
-	Index     int64
-	Timestamp int64
+	FileID int
+	Offset int64
 }
 
 type Keydir struct {
@@ -25,11 +24,10 @@ func NewKeydir() *Keydir {
 	}
 }
 
-func (k *Keydir) Add(key string, fileid int, index, timestamp int64) Item {
+func (k *Keydir) Add(key string, fileid int, offset int64) Item {
 	item := Item{
-		FileID:    fileid,
-		Index:     index,
-		Timestamp: timestamp,
+		FileID: fileid,
+		Offset: offset,
 	}
 
 	k.Lock()
diff --git a/proto/entry.pb.go b/proto/entry.pb.go
index 89f4b44..fca7d6a 100644
--- a/proto/entry.pb.go
+++ b/proto/entry.pb.go
@@ -19,11 +19,10 @@ var _ = math.Inf
 const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 
 type Entry struct {
-	CRC                  uint32   `protobuf:"varint,1,opt,name=CRC,proto3" json:"CRC,omitempty"`
+	Checksum             uint32   `protobuf:"varint,1,opt,name=Checksum,proto3" json:"Checksum,omitempty"`
 	Key                  string   `protobuf:"bytes,2,opt,name=Key,proto3" json:"Key,omitempty"`
-	Index                int64    `protobuf:"varint,3,opt,name=Index,proto3" json:"Index,omitempty"`
+	Offset               int64    `protobuf:"varint,3,opt,name=Offset,proto3" json:"Offset,omitempty"`
 	Value                []byte   `protobuf:"bytes,4,opt,name=Value,proto3" json:"Value,omitempty"`
-	Timestamp            int64    `protobuf:"varint,5,opt,name=Timestamp,proto3" json:"Timestamp,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -33,7 +32,7 @@ func (m *Entry) Reset()         { *m = Entry{} }
 func (m *Entry) String() string { return proto.CompactTextString(m) }
 func (*Entry) ProtoMessage()    {}
 func (*Entry) Descriptor() ([]byte, []int) {
-	return fileDescriptor_entry_4f5906245d08394f, []int{0}
+	return fileDescriptor_entry_3e91842c99935ae2, []int{0}
 }
 func (m *Entry) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Entry.Unmarshal(m, b)
@@ -53,9 +52,9 @@ func (m *Entry) XXX_DiscardUnknown() {
 
 var xxx_messageInfo_Entry proto.InternalMessageInfo
 
-func (m *Entry) GetCRC() uint32 {
+func (m *Entry) GetChecksum() uint32 {
 	if m != nil {
-		return m.CRC
+		return m.Checksum
 	}
 	return 0
 }
@@ -67,9 +66,9 @@ func (m *Entry) GetKey() string {
 	return ""
 }
 
-func (m *Entry) GetIndex() int64 {
+func (m *Entry) GetOffset() int64 {
 	if m != nil {
-		return m.Index
+		return m.Offset
 	}
 	return 0
 }
@@ -81,28 +80,20 @@ func (m *Entry) GetValue() []byte {
 	return nil
 }
 
-func (m *Entry) GetTimestamp() int64 {
-	if m != nil {
-		return m.Timestamp
-	}
-	return 0
-}
-
 func init() {
 	proto.RegisterType((*Entry)(nil), "proto.Entry")
 }
 
-func init() { proto.RegisterFile("entry.proto", fileDescriptor_entry_4f5906245d08394f) }
+func init() { proto.RegisterFile("entry.proto", fileDescriptor_entry_3e91842c99935ae2) }
 
-var fileDescriptor_entry_4f5906245d08394f = []byte{
-	// 134 bytes of a gzipped FileDescriptorProto
+var fileDescriptor_entry_3e91842c99935ae2 = []byte{
+	// 126 bytes of a gzipped FileDescriptorProto
 	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x4e, 0xcd, 0x2b, 0x29,
-	0xaa, 0xd4, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x05, 0x53, 0x4a, 0xa5, 0x5c, 0xac, 0xae,
-	0x20, 0x51, 0x21, 0x01, 0x2e, 0x66, 0xe7, 0x20, 0x67, 0x09, 0x46, 0x05, 0x46, 0x0d, 0xde, 0x20,
-	0x10, 0x13, 0x24, 0xe2, 0x9d, 0x5a, 0x29, 0xc1, 0xa4, 0xc0, 0xa8, 0xc1, 0x19, 0x04, 0x62, 0x0a,
-	0x89, 0x70, 0xb1, 0x7a, 0xe6, 0xa5, 0xa4, 0x56, 0x48, 0x30, 0x2b, 0x30, 0x6a, 0x30, 0x07, 0x41,
-	0x38, 0x20, 0xd1, 0xb0, 0xc4, 0x9c, 0xd2, 0x54, 0x09, 0x16, 0x05, 0x46, 0x0d, 0x9e, 0x20, 0x08,
-	0x47, 0x48, 0x86, 0x8b, 0x33, 0x24, 0x33, 0x37, 0xb5, 0xb8, 0x24, 0x31, 0xb7, 0x40, 0x82, 0x15,
-	0xac, 0x1e, 0x21, 0x90, 0xc4, 0x06, 0xb6, 0xdd, 0x18, 0x10, 0x00, 0x00, 0xff, 0xff, 0x07, 0x99,
-	0x47, 0xb9, 0x93, 0x00, 0x00, 0x00,
+	0xaa, 0xd4, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x05, 0x53, 0x4a, 0xc9, 0x5c, 0xac, 0xae,
+	0x20, 0x51, 0x21, 0x29, 0x2e, 0x0e, 0xe7, 0x8c, 0xd4, 0xe4, 0xec, 0xe2, 0xd2, 0x5c, 0x09, 0x46,
+	0x05, 0x46, 0x0d, 0xde, 0x20, 0x38, 0x5f, 0x48, 0x80, 0x8b, 0xd9, 0x3b, 0xb5, 0x52, 0x82, 0x49,
+	0x81, 0x51, 0x83, 0x33, 0x08, 0xc4, 0x14, 0x12, 0xe3, 0x62, 0xf3, 0x4f, 0x4b, 0x2b, 0x4e, 0x2d,
+	0x91, 0x60, 0x56, 0x60, 0xd4, 0x60, 0x0e, 0x82, 0xf2, 0x84, 0x44, 0xb8, 0x58, 0xc3, 0x12, 0x73,
+	0x4a, 0x53, 0x25, 0x58, 0x14, 0x18, 0x35, 0x78, 0x82, 0x20, 0x9c, 0x24, 0x36, 0xb0, 0x5d, 0xc6,
+	0x80, 0x00, 0x00, 0x00, 0xff, 0xff, 0x76, 0xd2, 0x3e, 0x83, 0x81, 0x00, 0x00, 0x00,
 }
diff --git a/proto/entry.proto b/proto/entry.proto
index 2e59b48..7c927d0 100644
--- a/proto/entry.proto
+++ b/proto/entry.proto
@@ -3,9 +3,8 @@ syntax = "proto3";
 package proto;
 
 message Entry {
-	uint32 CRC = 1;
+	uint32 Checksum = 1;
 	string Key = 2;
-	int64 Index = 3;
+	int64 Offset = 3;
 	bytes Value = 4;
-	int64 Timestamp = 5;
 }